The MEGARA spectrograph is equipped with a 4k x 4k CCD. Given the wide wavelength coverage of the instrument the detector chosen will be a deep-depleted E2V CCD231-84 (see left panel above). This detector provides very low fringing and relatively good efficiency in the blue end of the optical window, specially when combined with the astro-2 coating provided by E2V (see right panel above).
In the figure below we show the total efficiency curves of the instrument, including the telescope, fibers, spectrograph, and detector on the left and the transmission when the different disperser elements are included:
The main characteristics of the MEGARA CCD are summarized in the table below.
|CCD model||CCD 231-84 (Deep Depleted)|
|Number of pixels||4k x 4k 15 micron|
|Number of amplifiers||4 (in MEGARA it will be used in 2 ampl. mode)|
|Readout time||40 s (when using 2 amplifiers)|
|Readout noise||2 electrons|
|Efficiency||>90% between 400-800 nm|